Cervandonite-(Ce) Demartin F, Gramaccioli C M, Graeser S The Canadian Mineralogist 46 (2008) 423-430 The crystal structure of cervandonite-(Ce), an interesting example of As3+ - Si diadochy Locality: Alpine fissures at Pizzo Cervandone, Scherbadung, Central Alps Note: Chemistry from original description of the mineral. _database_code_amcsd 0006185 6.508 6.508 18.520 90 90 120 R3m atom x y z occ Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Ce 0 0 0 .44 .0203 .0225 .0225 .0159 .0113 0 0 Nd 0 0 0 .22 .0203 .0225 .0225 .0159 .0113 0 0 La 0 0 0 .21 .0203 .0225 .0225 .0159 .0113 0 0 Th 0 0 0 .06 .0203 .0225 .0225 .0159 .0113 0 0 Y 0 0 0 .03 .0203 .0225 .0225 .0159 .0113 0 0 U 0 0 0 .02 .0203 .0225 .0225 .0159 .0113 0 0 Ca 0 0 0 .02 .0203 .0225 .0225 .0159 .0113 0 0 Fe3+ .1682 .3365 -.1661 .417 .0309 .0286 .0585 .0157 .0292 .0020 .0040 Fe2+ .1682 .3365 -.1661 .140 .0309 .0286 .0585 .0157 .0292 .0020 .0040 Ti .1682 .3365 -.1661 .313 .0309 .0286 .0585 .0157 .0292 .0020 .0040 Al .1682 .3365 -.1661 .127 .0309 .0286 .0585 .0157 .0292 .0020 .0040 Sn .1682 .3365 -.1661 .003 .0309 .0286 .0585 .0157 .0292 .0020 .0040 As1 1/3 2/3 .3470 .58 .0183 .0232 .0232 .0084 .0116 0 0 As2 1/3 2/3 -.0156 .58 .0311 .0400 .0400 .0133 .0200 0 0 Si1 1/3 2/3 .3698 .42 .0291 Si2 1/3 2/3 .1928 .42 .0188 Si3 1/3 2/3 .1424 .42 .0188 Si4 1/3 2/3 -.0355 .42 .0291 O1 0 0 -.1404 .0710 O2 0 0 .1400 .0720 O3 .2024 .4048 .1673 .0291 O4 .0608 .5304 .3926 .0349 O5 .1926 .3853 -.0638 .0237 O6 1/3 2/3 .2824 .0380 O7 1/3 2/3 .0532 .0230